Password Attacks
hashcat
hashcat is the fastest hash cracker there is, because it runs on your GPU. Where
John is flexible and clever, hashcat is raw speed — given a supported hash type
and decent hardware, it chews through billions of candidates a second. It supports
hundreds of hash modes (each has a number you pass with -m) and several attack
modes (-a): straight wordlist, combinator, brute-force/mask, and hybrid. For
serious offline cracking it’s the tool.
Official-repo package; Security → Password Attacks → hashcat. Like John, it’s
a single menu entry and ships a set of *2hashcat extractors for pulling hashes
out of things like BitLocker volumes and LUKS containers.
The help it prints
hashcat’s help lists hundreds of hash and attack modes; this is the top of it — usage and the core options:
hashcat (v7.1.2) starting in help mode
Usage: hashcat [options]... hash|hashfile|hccapxfile [dictionary|mask|directory]...
- [ Options ] -
Options Short / Long | Type | Description | Example
================================+======+======================================================+=======================
-m, --hash-type | Num | Hash-type, references below (otherwise autodetect) | -m 1000
-a, --attack-mode | Num | Attack-mode, see references below | -a 3
-V, --version | | Print version |
-h, --help | | Print help. Use -hh to show all supported hash-modes | -h or -hh
--quiet | | Suppress output |
--hex-charset | | Assume charset is given in hex |
--hex-salt | | Assume salt is given in hex |
--hex-wordlist | | Assume words in wordlist are given in hex |
--force | | Ignore warnings |
--deprecated-check-disable | | Enable deprecated plugins |
--status | | Enable automatic update of the status screen |
--status-json | | Enable JSON format for status output |
--status-timer | Num | Sets seconds between status screen updates to X | --status-timer=1
--stdin-timeout-abort | Num | Abort if there is no input from stdin for X seconds | --stdin-timeout-abort=300
--machine-readable | | Display the status view in a machine-readable format |
--keep-guessing | | Keep guessing the hash after it has been cracked |
--self-test-disable | | Disable self-test functionality on startup |
--loopback | | Add new plains to induct directory |
--markov-hcstat2 | File | Specify hcstat2 file to use | --markov-hcstat2=my.hcstat2
--markov-disable | | Disables markov-chains, emulates classic brute-force |
--markov-classic | | Enables classic markov-chains, no per-position |
--markov-inverse | | Enables inverse markov-chains, no per-position |
-t, --markov-threshold | Num | Threshold X when to stop accepting new markov-chains | -t 50
--metal-compiler-runtime | Num | Abort Metal kernel build after X seconds of runtime | --metal-compiler-runtime=180
--runtime | Num | Abort session after X seconds of runtime | --runtime=10
--session | Str | Define specific session name | --session=mysession
--restore | | Restore session from --session |
--restore-disable | | Do not write restore file |
--restore-file-path | File | Specific path to restore file | --restore-file-path=x.restore
-o, --outfile | File | Define outfile for recovered hash | -o outfile.txt
--outfile-format | Str | Outfile format to use, separated with commas | --outfile-format=1,3
--outfile-json | | Force JSON format in outfile format |
--outfile-autohex-disable | | Disable the use of $HEX[] in output plains |
--outfile-check-timer | Num | Sets seconds between outfile checks to X | --outfile-check-timer=30
--wordlist-autohex-disable | | Disable the conversion of $HEX[] from the wordlist |
-p, --separator | Char | Separator char for hashlists and outfile | -p :
--stdout | | Do not crack a hash, instead print candidates only |
--show | | Compare hashlist with potfile; show cracked hashes |
--left | | Compare hashlist with potfile; show uncracked hashes |
--username | | Enable ignoring of usernames in hashfile |
--dynamic-x | | Ignore $dynamic_X$ prefix in hashes |
--remove | | Enable removal of hashes once they are cracked |
--remove-timer | Num | Update input hash file each X seconds | --remove-timer=30
--potfile-disable | | Do not write potfile |
--potfile-path | File | Specific path to potfile | --potfile-path=my.pot
--encoding-from | Code | Force internal wordlist encoding from X | --encoding-from=iso-8859-15
--encoding-to | Code | Force internal wordlist encoding to X | --encoding-to=utf-32le
--debug-mode | Num | Defines the debug mode (hybrid only by using rules) | --debug-mode=4
--debug-file | File | Output file for debugging rules | --debug-file=good.log
--induction-dir | Dir | Specify the induction directory to use for loopback | --induction=inducts
--outfile-check-dir | Dir | Specify the directory to monitor 3rd party outfiles | --outfile-check-dir=x
--logfile-disable | | Disable the logfile |
--hccapx-message-pair | Num | Load only message pairs from hccapx matching X | --hccapx-message-pair=2
--nonce-error-corrections | Num | The BF size range to replace AP's nonce last bytes | --nonce-error-corrections=16
--keyboard-layout-mapping | File | Keyboard layout mapping table for special hash-modes | --keyb=german.hckmap
--truecrypt-keyfiles | File | Keyfiles to use, separated with commas | --truecrypt-keyf=x.png
--veracrypt-keyfiles | File | Keyfiles to use, separated with commas | --veracrypt-keyf=x.txt
--veracrypt-pim-start | Num | VeraCrypt personal iterations multiplier start | --veracrypt-pim-start=450
--veracrypt-pim-stop | Num | VeraCrypt personal iterations multiplier stop | --veracrypt-pim-stop=500
-b, --benchmark | | Run benchmark of selected hash-modes |
--benchmark-all | | Run benchmark of all hash-modes (requires -b) |
--benchmark-min | | Set benchmark min hash-mode (requires -b) | --benchmark-min=100
--benchmark-max | | Set benchmark max hash-mode (requires -b) | --benchmark-max=1000
--speed-only | | Return expected speed of the attack, then quit |
--progress-only | | Return ideal progress step size and time to process |
-c, --segment-size | Num | Sets size in MB to cache from the wordfile to X | -c 32
--bitmap-min | Num | Sets minimum bits allowed for bitmaps to X | --bitmap-min=24
--bitmap-max | Num | Sets maximum bits allowed for bitmaps to X | --bitmap-max=24
--bridge-parameter1 | Str | Sets the generic parameter 1 for a Bridge |
--bridge-parameter2 | Str | Sets the generic parameter 2 for a Bridge |
--bridge-parameter3 | Str | Sets the generic parameter 3 for a Bridge |
--bridge-parameter4 | Str | Sets the generic parameter 4 for a Bridge |
... (abridged)
Run `hashcat --help` in the terminal for the complete option list.Examples
# Dictionary attack on MD5 hashes (mode 0 = MD5)
hashcat -m 0 -a 0 hashes.txt /usr/share/wordlists/rockyou.txt
# NTLM hashes with a wordlist + rules
hashcat -m 1000 -a 0 hashes.txt rockyou.txt -r /usr/share/hashcat/rules/best64.rule
# Brute-force mask: eight lowercase letters
hashcat -m 0 -a 3 hashes.txt ?l?l?l?l?l?l?l?l
# Let hashcat guess the mode (it prints candidates)
hashcat --identify hashes.txt
# Show cracked results
hashcat -m 0 hashes.txt --showPick -m from the mode list in the full --help; getting the hash type right is
half the battle.